php - 脚本中出现多个 PHP "header(url)"， "Cannot modify header information"错误

Question

嘿，我有一些脚本，如果满足某些条件，则应该更改页面的 url，如果不满足，则应该更改其他位置。

我收到此错误:

Warning: Cannot modify header information - headers already sent by (output started at /hermes/bosweb25c/b1401/ipg.website/process.php:7) in /hermes/bosweb25c/b1401/ipg.website/process.php on line 53

这是我的 PHP。我很确定它与 if 语句有关，但在我上传到我的网络主机之前，它在我的 WAMP 服务器上运行良好。

<?php
session_start();
$con = mysql_connect('website', 'members_db_admin', 'password'); 
if (!$con) { 
    die('Could not connect: ' . mysql_error()); 
} 
echo 'Connected successfully<br />'; 

// make members the current db
$db_selected = mysql_select_db('members_db', $con);
if (!$db_selected) {
    die ('Can\'t use members database : ' . mysql_error());
}
$hash_password = md5($_POST['password']);

$email = $_POST['email'];

$result = mysql_query("SELECT email,password FROM `members` WHERE email = '$email'");
if (!$result) {
    echo 'Could not run query: ' . mysql_error();

}

$row = mysql_fetch_row($result);

if ($row[0] != $email && $hash_password != $row[1])
{
    $query = "INSERT INTO members (email, password)
    VALUES('".$_POST['email']."','".$hash_password."')";

    // Perform Query
    $result2 = mysql_query($query);

    // Check result
    // This shows the actual query sent to MySQL, and the error. Useful for debugging.
    if (!$result2) {
        $message  = 'Invalid query: ' . mysql_error() . "\n";
        //$message .= 'Whole query: ' . $query;
        die($message);
    }   
$_SESSION['email']=$_POST['email'];
$_SESSION['password']=$hash_password;
$_SESSION['loggedin']="YES";
$url = "Location: /welcome.php";
header($url);
}
$_SESSION['email']=$_POST['email'];
$_SESSION['password']=$hash_password;
$url = "Location: /checklogin.php";
header($url);
?>

Answer 1

您的问题是echo 'Connected successfully<br />'; 。在使用 header() 设置标题之前，您无法打印任何内容。称呼。确保您没有任何 echo在您的header()之前调用.